Working Prototype Of A Talking Voltmeter Information Technology Essay

1.1: Introduction

Voltmeter as we know is used to mensurate electromotive force in circuits. It is a common pattern to step and expression at the readings or measurings on the LCD of the voltmeter. At times, by looking at the readings and at the same clip mensurating the circuit utilizing probes causes the connexion between the trial points to acquire loose or gets disconnected. As a human we can non make two separate things and concentrate our eyes on both the circuit and the voltmeter.

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This has besides been a job for so many pupils during laboratory Sessionss and because of this, the reading of the measuring might be wrong or erroneously measured. Sometimes to mensurate a complex circuit need careful handling of the investigation to non touch the wrong point as non to short circuit the circuit itself. Two people were required sometimes to mensurate a circuit, one to keep the investigation in and another to read and compose down the reading of the measuring. I have experienced it myself in research lab session and happen it hard as there is no demand to hold two people to mensurate a circuit.

An thought popped out in my head as how to work out this job to ease the load of a individual who is utilizing the voltmeter which is to make a Talking Voltmeter. By making this speaking voltmeter, a individual who uses a voltmeter to mensurate can now mensurate a trial point without seeing the LCD to acquire the consequences. The readings will be read out as a sound via a little talker to enable the user to hear the consequences.

By holding sound as the end product, the measurings can be easy gained and the individual who measures the circuit will hold an easier manner of using his clip as the individual will non be acquiring any incorrect readings. This could salvage clip and avoid unneeded emphasis.

1.2: Aim

The chief intent of implementing this undertaking is to hold a on the job paradigm of a speaking voltmeter. By get downing this undertaking, smaller aims are achieved such as:

Learn how to construct a circuit

Learn how to plan a microcontroller

Learn scheduling

Learn trouble-shooting

Learn PCB etching

Learn how to incorporate the circuit to work with the software/coding

Be able to utilize a voltmeter to acquire a reading to compare with the speaking voltmeter

Able to show the frequence reading

Able to corroborate the reading with the original value

Be able to show the LCD is working

Learn how to plan sound/voice into the microcontroller

Able to show the voice end product is the right reading with the LCD show

1.3: Undertaking Flow






Final Project Report



Figure 1: Undertaking Flow Diagram

At the start of the undertaking, research is done to guarantee all the information sing the undertaking is compiled and further studied. After the research procedure, planning is afoot to do all the necessary readying to get down the undertaking. In planning, a batch of things are planned such as the clip frame, how to acquire constituents, basic workings of the undertaking, work flow and besides budgeting.

The following measure will be planing the undertaking from the circuit diagram to the procedure flow of the undertaking. After planing, trouble-shooting is half-baked to do certain there are no jobs in the design of the hardware or the package. Testing is done to do certain that the circuit works as planned and can be able to do measurings. Further troubleshooting and testing is done when there were some more bugs in the circuit and scheduling. Finally, concluding studies are prepared.

1.4: Undertaking AIMS

The purpose of this undertaking is to heighten the current voltmeter so that the voltmeter has the capableness to end product voice or sound when measured. This will do the life of an user who uses this speaking voltmeter to mensurate readings in a voltmeter.

1.5: Planning

Throughout this full undertaking, a proper planning has been carried out to indentify the undertakings and besides as a guideline to finish this undertaking. This undertaking was organized based on thoughts from literature study and treatment through many beginning and information gather from cyberspace web sites and books. The undertakings are arranged as follow:

Literature Survey

Undertaking Design ( Hardware & A ; Software )

Circuit Testing

Undertaking Construction


1.6: Undertaking EXPECTATIONS

The intent of this undertaking is to prove and dispute the academic cognition that hasbeen gained so far throughout our full class period of two old ages. This undertaking requires us to use cognition from all our topics.

All parts and packages of this undertaking are expected to work good in order to accomplish perfect undertaking map.

In approaching old ages, an advanced version of this undertaking will be built incorporated with the latest engineering and more advanced characteristics. This undertaking is expected to be the theoretical account for future speaking voltmeter around the universe.



Mode Selector

LCD Display


Voice Playback


Figure 2: Block Diagram of Talking Voltmeter

The block diagram of the speaking voltmeter is provided supra. As we can see above, the PIC16F877A controls all the input and end product of the circuit. The probes Acts of the Apostless as an end product where it is used to mensurate circuits and the signal is send to the microprocessor ( MPC ) . Depending on the manner picker, either electromotive force or frequence the MCU will treat the input and calculates the end product and displays it on the LCD show.

When the end product is displayed on the LCD show, signal will be sent to the voice playback bit and it will end product voice entering to the talker. All this is feasible becauseIn this undertaking, the C+ linguistic communication has been used as the package programming linguistic communication. C+ linguistic communication is a multi-paradigm scheduling linguistic communication embracing functional, generic, imperative, object-oriented ( class-based ) , and component-oriented scheduling subjects. C+ linguistic communication is intended to be a simple, general intent, modern, object-oriented, and type-safe scheduling linguistic communication. C+ is intended to be suited for composing applications for both hosted and embedded systems, runing from the really big that usage sophisticated operating systems, down to the really little holding dedicated maps. In C+ linguistic communication, memory reference arrows can merely be used within blocks specifically marked as insecure, and plans with insecure codifications need appropriate permissions to run. Most object entree is done through safe object mentions, which ever either point to a “ unrecorded ” object or have the chiseled void value ; it is impossible to obtain a mention to a “ dead ” object ( one which has been garbage collected ) , or to random block of memory. An insecure arrow can indicate to an case of a value-type, array, twine, or a block of memory allocated on a stack. Code that is non marked as insecure can still hive away and pull strings arrows through the System. Hence, this is the speaking voltmeter sum-up of its map.

1.8: Undertaking DEVELOPMENT FLOW

In undertaking development planning, the procedure flow as shown in figure below is followed. This procedure flow chart was used as a guideline to understand the progressing of the undertaking position. In order to hold efficient undertaking planning, the undertaking development procedure was break down into 2 major subdivisions, which are hardware Development and Software Development.

Figure 3: Undertaking Development Flow Chart


2.1: Introduction

A digital voltmeter is normally used by all. It is easy accessed and easy used. A digital voltmeter can read values up to two denary points. It is normally used by pupils to carry on research lab assignments.

The digital voltmeter merely deficiency of one thing, it can non read out the value that a individual is mensurating. This has made the life of pupils and besides other users harder as they need to look at the voltmeter to cognize the reading. It can besides be troublesome if the circuit that are being step is big and the voltmeter can non be near to the user to see the readings on the voltmeter.

Figure 4: Digital Voltmeter

The image provided above shows the regular voltmeter which is available in the market right now and is widely used by all. Although utilizing these types of voltmeter gives out right reading, it is missing voice to inform the user of the reading or the value on the voltmeter.

If the marketed regular voltmeter comes with a voice which tells out the readings, it would do mensurating easier and faster.

2.1.1: What is DPCM? [ 1 ]

DifferentialA pulseA codeA transition ( DPCM ) is a process of change overing an parallel into a digital signal in which an parallel signal is sampled and so the difference between the existent sample value and its predicted value ( predicted value is based on old sample or samples ) is quantized and so encoded organizing a digital value.

DPCM codification words represent differences between samples unlike PCM where codification words represented a sample value.

Basic construct of DPCM – coding a difference, is based on the fact that most beginning signals show important correlativity between consecutive samples so encoding utilizations redundancy in sample values which implies lower spot rate.

Realization of basic construct ( described above ) is based on a technique in which we have to foretell current sample value based upon old samples ( or sample ) and we have to encode the difference between existent value of sample and predicted value ( the difference between samples can be interpreted as anticipation mistake ) .

Because it ‘s necessary to foretell sample value DPCM is signifier of prognostic cryptography.

DPCM compaction depends on the anticipation technique, well-conducted anticipation techniques lead to good compaction rates, in other instances DPCM could intend enlargement comparing to regular PCM encryption.

Figure 5: DPCM encoder ( sender )

2.2: Component AND PROPERTIES

In this bomber chapter, treatments will be made on constituents chosen for this undertaking and its belongingss which best suits to build the Talking Voltmeter and its applications.


The PIC chosen for this undertaking is 40-pin PIC16F877A as shown in figure 4. The 16F877A is one of the most popular PIC microcontrollers and it is easy to interface because it comes in a 40 pin PDIP pin out and it has many internal peripherals. A The 40 pins make it easier to utilize the peripherals as the maps are spread out over the pins. A

Figure 6: Diagram of PIC16F877A

It is under the 8-bit category microcontroller. It has 8K of FLASH Program Memory, 10-bit A/D convertors, 33 I/O pins, 368 byte RAM, 256 byte EEPROM, in-circuit consecutive scheduling and other characteristics. It besides has RISC ( Reduced Instruction Set Computer ) architecture.A One of the chief advantages is that each pin is merely shared between two or three maps so it ‘s easier to make up one’s mind what the pin map.

A disadvantage of the device is that it has no internal oscillator so it needs an external crystal oscillator.This PIC can besides be reprogrammed and erased up to 10,000 times. Therefore it is utile for new merchandise development stage.

Figure 7: Bubble Diagram of PIC16F877A

Figure 5 above shows the bubble diagram of PIC16F877A. All the resources of the PIC are shown clearly and significantly, they are all brassy effaceable and re-programmable.

2.2.2: Display Unit ( LCD )

The 16×2 characters LCD has 14 pins as shown in figure 10 below. It has 8 informations coach pins that are DB0 to DB7 and they can back up both the 4-bit and 8-bit interfacing. Merely data pins of DB4 to DB7 of the LCD are used when interfacing 4-bit while all of the DB0 to DB7 are used for 8-bit interfacing. The direction registry ( IR ) and the informations registry ( DR ) of the LCD can be controlled by the MCU. Before get downing the internal operation of the LCD, control information is temporarily stored into these registries to let interfacing with assorted MCUs, which operate at different velocities, or assorted peripheral control devices. This internal operation of the LCD is determined by signals sent from the MCU. These signals include register choice signal ( RS ) and read/write ( R/W ) , make up the LCD instructions.

There are four classs of instructions:

Designate LCD map such as show format, informations length, etc

Set internal RAM reference

Perform informations transportation with internal Random-access memory

Perform assorted maps.

Figure 8: 16X2 LCD Display Unit

The maps of each pin of the LCD are shown in Table 1.

Pin No.








+Ve Supply






Register Select









Data Bit 0



Data Bit 1



Data Bit 2



Data Bit 3



Data Bit 4



Data Bit 5



Data Bit 6



Data Bit 7

Table 1: LCD pin constellation

2.2.3: Voice Playback Device ( ISD4003 )

The ISD4003 ChipCorder Series provides high-quality, 3-volt, and single-chip record/playback solutions for 4 to 8 proceedingss messaging applications ideally for cellular phones. It is C-MOS based device which includes on-chip oscillator, anti-aliasing filter, smoothing filter, AutoMute characteristic, audio amplifier, and high denseness multilevel Flash memory array. The ISD 4003 is designed to be used with a microprocessor based system. Address and control are accomplished through a Consecutive Peripheral Interface ( SPI ) or Microwire Serial Interface to minimise pin count.

Figure 9: ISD4003 ChipCorder Series

All the recordings are stored in the on-chip Flash memory cells. The voice and audio signals are straight stored onto memory array in their memory array in their natural signifier, supplying high-quality voice reproduction.

Table 2: Merchandise Summary Of ISD4003 Series

For this undertaking, ISD4003-04M is used. It has 4 proceedingss of continuance and its sampling rate is 8 kilohertz. ISD4003-04M is chosen because of the address quality options where the higher the trying rate is, the higher quality address can be outputted. But by desiring higher quality, the continuance of the bit is decreased. By mentioning to the tabular array provided above, the differences are stated and can be compared easy.

2.2.4: Voltage Regulator

Voltage regulator is a normally used electrical constituent in an electrical circuit. The map of the electromotive force regulator is to change over AC or DC Voltage into DC Voltage and to bring forth a comparatively coveted changeless electromotive force. The usage of electromotive force depends on the map of the circuit and application. There are two sorts of electromotive force regulators, inactive electromotive force regulators and active electromotive force regulators. A inactive electromotive force regulator reduces the input electromotive force to a desired value and removes the extra energy by agencies of heat. Normally, a heat sink is attached to the electromotive force regulator in order to disperse the heat. Whereas a active electromotive force regulator increases the input electromotive force to a desired value. This is achieved by a of negative feedback cringle to command the electromotive force.

Figure 10: Voltage Regulator

For this undertaking, LM7805 is chosen as the electromotive force regulator shown in figure 8above. It is connected directly to AC power where a DC power arranger so supplies supply to the electromotive force regulator so that the electromotive force regulator can supply a changeless end product electromotive force of 5V and the maximal end product current is 1A to power up the circuit.

2.2.5: Capacitor

Capacitors are widely used in an electrical circuit. It serves as a device which shops energy in the signifier of an electrostatic field. It is used for several maps such as smoothing power end product, barricading direct current and merely leting jumping current to go through through.

2.2.6: Voice Recording and Playback ( ISD2560 )

Winbond ‘s ISD2560 ChipCorder Series provides high quality playback and entering for 60 seconds. The CMOS devices include an on-chip oscillator, microphone pre-amplifier, automatic addition control, anti-aliasing filter, smoothing filter, talker amplifier, and high denseness multi-level storage array. In add-on, the ISD2560 microcontroller is compatible, leting complex messaging and turn toing to be achieved. Recordings are stored into on-chip non-volatile memory cells

Figure 11: ISD2560

2.2.7: AMPLIFIER ( TDA2003 )

TDA2003 is normally used in auto wireless sound as amplifier. It has besides complete safe operation protection against DC and AC short circuit between all pins and land, thermic over-range, and burden shit electromotive force surge up to 40V.

Figure 12: TDA2003


3.1: Circuit Execution


Figure 13: PIC Circuit

Figure 11 above shows the circuit diagram for the Talking Voltmeter. The whole operation of this control system is controlled by PIC16F877A microcontroller which is already programmed by utilizing the C+ linguistic communication. The chief intent of this Talking Voltmeter is to mensurate electromotive force and that outputs whatever being measured through talkers, it ‘s one of its sorts and an indispensable tool for lab work.PIC16F877A is 5V but the power supply is 12V. If the electromotive force is more than 5V, it can do the PIC microcontroller malfunction because the PIC can non back up more than 5V power supply. So, the LM7805 electromotive force regulator is applied in this control system. LM7805 is used to change over changing input electromotive force and bring forth a changeless end product electromotive force of 5V. For maximal electromotive force ordinance, capacitance in analogue between the land leg and end product leg is recommended. This capacitance is used to filtrate up the signal and bring forth a smooth end product signal. Since PIC16F877A does non hold an internal clock a crystal oscillator of 8MHz is connected as external clock beginning to OSC1 input and OSC2 end product where CLKOUT has 1/4 the frequence of OSC1, and denotes the direction rhythm rate.

A scheduling slot in the device is besides designed to ease the user to put or alter the demands without taking the MCU. Pins 17 to 20 are used to direct instructions to the voice playback bit ( ISD4003-04MS ) .


Figure 14: Power Supply Circuit

Figure 12 above shows the LM7805 which is connected to a 12V beginning and provides a changeless 5V end product. The end product is used to provide power to the MCU. The end product is besides used to power up the voice playback device on the PCB board.

A rectifying tube ( D3 ) is used to forestall rearward current from the 5V supply. In add-on, such device normally incorporate over current protection and can defy a direct short-circuit placed across their end product terminuss. LED0 is used to bespeak that the end product electromotive force is a changeless 5V.


Figure15: Voice Playback Circuit

Based on the circuit on figure 13, circuit was built to prove out the ISD2560 from the information which was available on the datasheet. The following tabular array below is the pin assignment which was provided in the datasheet.



Pin Function




Address pin 0




Address pin 1




Address pin 2




Address pin 3




Address pin 4




Address pin 5




Address pin 6




Address pin 7




Address pin 8




Address pin 9




Chip enable ) low to enable device operation )




Power down ( high to put device in standby manner )








End-Of_message ( pulse depression at the terminal of each message )




Overflow ( pulse low at the terminal of memory array )




Supply electromotive force ( digital )

Connected to 5V



Supply electromotive force ( parallel )

Connected to 5V



Land ( digital )

Connected to land



Land ( parallel )

Connected to land

Table 3: Pin Assignments of ISD2560

Circuit was constructed as in the figure above. The MCU ( PIC16F877A ) circuit was constructed individually and the circuit for voice playback was constructed individually. This is to guarantee that the MCU can be interfaced with any circuit by pull stringsing the pins.

This was done to guarantee that the voice playback circuit are operated individually in instance there are any replacings or alteration which might be involved in the close hereafter. This is besides to guarantee that the

3.1.4: LCD Display Circuit ( 16×2 )

As for this circuit it is straight connected to the PORT D and PORT C of the PIC. The LCD panel ‘s Enable and Register Select is connected to the Control Port. The Control Port is an unfastened aggregator / unfastened drain end product. The Data coach is non set into rearward way which means the informations coach pins are straight connected to the PORT D, Therefore the R/W line of the LCD panel is difficult wired into write manner, this will do no coach conflicts on the information lines. As a consequence the user can non read back the LCD ‘s internal Busy Flag which tell the user if the LCD has accepted and finished treating the last direction. This job is overcome by infixing known holds into the plan. Hence the show LCD portrays the character of the end product.

Figure 16: LCD conventional

3.2: Undertaking Construction

PCB Board Etching

The PCB Board etching procedure can be categorized to a few stairss. It follows the sequence below:

3.2.1: Ultraviolet Exposure

The PCB which was designed and printed is put onto the PCB. ( Printed subdivision downwards ) it is so put inside the UV box for exposure around 8-10 proceedingss.

Figure 17: Ultraviolet procedure

3.2.2: Development

After the UV exposure procedure, the PCB board is so taken. The following measure is to rinse the open PCB with a recommended sum of Sodium Metasilicate assorted with H2O. The procedure is done when you can see the design of your circuit in green and the remainder in Cu. The PCB Board is so washed with tap H2O to take the balance of Sodium Metasilicate.

Figure 18: Procedure to rinse the PCB with Sodium Metasilicate

3.2.3: Etching

This is the concluding procedure of the PCB Board Etching. A recommended sum of ferrous Chloride is assorted with hot H2O inside a tray to organize the needful etching solution. The developed PCB Board is so put inside the tray which contains the ferrous Chloride solution and gently shaken. This procedure is to be carried out until all subdivisions of unwanted Cu are etching, go forthing merely the designed circuit.

Figure 19: After etching

3.2.4: Drilling

A broad assortment of drills can be used for boring constituents leg holes into the PCB but it depends on the size of the designed circuit. For this Talking Voltmeter Designcircuits, 0.8mm drills are used.

Figure 20: Drilling Procedure

3.2.5 Soldering

After the boring procedure, the constituents are so fitted onto the PCB Board, checked for mistakes so soldered. The soldering procedure must be done with attention because the het bonding Fe can be risky.

Figure 21: Soldering the constituents

Chapter 4: Software DEVELOPMENT



If PC5=0 and PC4=1

If PC5=1 and PC4=0

Sub Convert_volt

Sub display_volt

Sub counter

Sub display_counter

Sub play_voice

Sub play_voice_freq






Figure 22: Main Flowchart

As shown in the figure above, PB3 and PB4 act as a switch on the hardware. When PB3 is low and PB4 is high it will travel to voltage measurement protocols. Where else when PB3 is high and PB4 is low, it will travel to frequency mensurating protocol.

Each of the protocol has subprograms which plays a large function in operating and giving out values on the LCD. Each subprogram has its ain maps. Further treatment will be made on the subprograms flowchart in the undermentioned chapter.


Volt = ( measure*50 ) /1023

Volt1 = V mod 10

Volt2 = volt/10


4.2: Convert_volt Subroutine

Figure 23: Convert_volt Flowchart

Figure 14 shown above shows the computation which is done to change over the digital signal into denary. The computation is utilizing 1024 spots to divide out its spot to organize 5V upper limit. For illustration, if the input is 512 so electromotive force value will be 2.5V and for 819 so the end product will be 4V.

The volt1 and volt2 is used to make the denary points for the LCD show. For illustration, ( volt2 ) . ( volt1 ) V, these are the assignment which was done for volt1 and volt2 where each value will be shown at their several topographic point.


LCD shows:

Digital = “ “

DC Volt = “ “


4.3: Display_volt Subroutine

Figure 24: Display_volt Flowchart

The subprogram which is shown in figure 15 displays the deliberate informations on the LCD show. For illustration, Digital = 512 and DC Volt = 2.5V.


LCD shows:

Frequency = “ “


4.4: Display_counter Subroutine

Figure 25: Display_counter Flowchart

The subprogram which is shown in figure 16 displays the deliberate informations on the LCD show. For illustration, Frequency = 50 Hz.


If volt1 or volt2 =1

If volt1 or volt2 =2

If volt1 or volt2 =3

If volt1 or volt2 =4

If volt1 or volt2 =5

Play Sound one

Play Sound two

Play Sound three

Play Sound four

Play Sound five











Yes4.5: Play_voice Subroutine

Figure 26: Play_voice Flowchart

In this subprogram, a simple if else statement is used to play the voice end product to the talker. The volt1 and volt2 will cipher the value and the value will so be evaluated and so given as voice end product.

It will so play the end product given on the LCD show and outputs it out through the talker. For illustration, if 1V is measured so it will voice out as 1V.


If freq1 or freq2 or freq3 or freq4 & lt ; =5

If freq1 or freq2 or freq3 or freq4 & gt ; =5

Less than 5

More than 5





Yes4.6: Play_voice_freq Subroutine

Figure 27: Play_voice_freq Flowchart

Based on figure 27, the simple if else statement is besides used merely as the play_voice subprogram. The basic map is every bit same as the play_voice subprogram and the flow chart given here is divided into two subdivisions, less than five and more than five. This is done to do certain the individual who is reading this will hold a better apprehension of the flow chart and non to mess up the whole flow chart until the reader can non understand anything and in the terminal gets confused.

If freq1 or freq2 or freq3 or freq4 =1

If freq1 or freq2 or freq3 or freq4 =2

If freq1 or freq2 or freq3 or freq4 =3

If freq1 or freq2 or freq3 or freq4 =4

If freq1 or freq2 or freq3 or freq4 =1

Play Sound one

Play Sound two

Play Sound three

Play Sound four

Play Sound five













Figure 28: Less Than 5 Flowchart

As we can see in this figure 28, this flow chart shows the less than 5 which are in figure 27. The ground for this dislocation is to hold readability for anyone who is reading this study.

If freq1 or freq2 or freq3 or freq4 =6

If freq1 or freq2 or freq3 or freq4 =7

If freq1 or freq2 or freq3 or freq4 =8

If freq1 or freq2 or freq3 or freq4 =9

If freq1 or freq2 or freq3 or freq4 =0

Play Sound six

Play Sound 7

Play Sound eight

Play Sound nine

Play Sound nothing













Figure 29: More Than 5 Flowchart

As we can see in this figure 29, this flow chart shows the more than 5 which are in figure 27. The ground for this dislocation is to hold readability for anyone who is reading this study.

Chapter 5: Problems and Solutions

Problem 1:

Over exposure of the UV board to the UV exposure.

UV board is used for the undertaking. The first job which occurred was the connexion job due to the UV exposure. The exact exposure clip is 8 proceedingss. Unfortunately the board was overexposed and the consequence was bad. Some of the Cu lines were non connected. This was because the UV visible radiation penetrated the black country. So another PCB was tried.

Solution 1:

Expose the UV board at the exact clip.

Problem 2:

Excessively much ferrous chloride was used and besides overexposed the board.

It was caused during the etching procedure. The existent etching clip is 8 to 10 proceedingss. Ferric chloride is used to rinse off the unwanted Cu bed. Ferric chloride is assorted with warm H2O. The etching procedure will be shortened up when the solution is warm but yet the board was exposed for 10 proceedingss. So some of the Cu lines were washed out and non connected any longer.

Solution 2:

The appropriate sums of ferrous chloride are used and do non overexpose the board.

Problem 3:

Bad soldering accomplishments caused short circuit and connexion jobs.

Before the circuit is done on a PCB board, bread board is used to prove if the circuit was working. But it failed to work.

The consequence of the troubleshooting, found that there is no electromotive force go throughing through to the PIC. That means there was no electromotive force to power up the PIC. It is assumed that this was because of the deficiency of soldering accomplishments.

Solution 3:

Improve soldering accomplishments.

Problem 4:

PCB design ( Components ‘ legs were excessively close )

Few jobs were encountered in the PCB design. The Cu lines were excessively close to each other and it was difficult to solder the constituents. After all the constituents are soldered, there were excessively many short circuits. So a new PCB design are decided and redone with more infinite for the constituents.

Solution 4:

The constituents legs must non be excessively close to each other during the PCB design.

Problem 5:

Components were connected wrongly.

There was a error where the positive leg of capacitance was connected to the negative terminus of the power supply. The consequence was the amplifier did n’t work.

Solution 5:

All the constituents must be connected right.

Problem 6:

Some of the pins on the microprocessor were non giving out any end products.

Solution 6:

Used the multimeter to prove and mensurate the pins and found out the pins are unserviceable. Then tested out other pins and decided to utilize other pins as the input. In the terminal, most of the pins on the microprocessor were giving job and the MCU was changed to a newer one.

Problem 7:

LCD show was unresponsive and were winking.

Solution 7:

Further analysis and testing by utilizing the multimeter, solder contact was found near to the information pins and it was barricading or disrupting the information flow. The job was corrected by re-soldering the LCD show.

Problem 8:

The ISD2560 was unresponsive to the scheduling and was acquiring hot when power is switched on.

Solution 8:

Since the ISD2560 was salvaged from another circuit, it was found that the bit was damaged and further soldering to the PCB board damaged it more. The heat was generated from the inordinate electromotive force which was supplied because the power was supplied from DC arranger and was non through electromotive force regulator. It is suspected that the bit is burned. This bit is so replaced by ISD4003-04MS bit.

Problem 9:

By utilizing mathlab, bring forthing sound from wave form files was unsuccessful

Solution 9:

A playback device can be used to replace this. ISD 2560 can be used to record and play sounds. It can besides be used for this undertaking. First the sound is recorded and saved in the memory blocks. Then when it is clip, the playback characteristic can be called by utilizing the MCU and direct the bid to the playback device to name the sounds from its memory.

Problem 10:

The electromotive force regulator circuit is non runing at the specified degree which is at 5V.

Solution 10:

After trouble-shooting, it was found that the rectifying tube was in contrary. It was a simple human mistake which was made during soldering procedure. The rectifying tube was so replaced and soldered back once more and the electromotive force was tested by utilizing multimeter. The consequences was 5V, therefore the electromotive force regulator is working decently.

Chapter 6: Testing

The speaking voltmeter was tested to compare the consequences to an existent voltmeter so can the mistake can be determined. Here are the tabular array provided below:

Talking Voltmeter ( V )

Normal Voltmeter ( V )

% Mistake
















Table 4: Voltmeter Readings for Voltage Measurement

Talking Voltmeter ( Hz )

Function Generator ( Hz )

% Mistake
















Table 5: Voltmeter Readings for Frequency Measurement

From the provided informations above we can see that there is some per centum of mistake with the speaking voltmeter which was designed. This mistake can be due to external mistake or internal mistakes such as noise.

It is besides noted here that the speaking voltmeter can merely demo values up to one decimal point. This limits the speaking voltmeter from demoing the right value. Recalibration of the voltmeter was done and the consequences are about the same as shown above. Decision was made that the design itself affected this values and future development of this undertaking will do it more accurate.

6.1: Speed OF Execution

Each mode the Talking Voltmeter was executed rapidly. The LCD was able to acknowledge a alteration in electromotive force really fast. The Talking Voltmeter took samples every 20ms and updated about immediately on the screen for the figure of samples at that minute. For the frequence manner, the optimal scope of operation was from 1Hz to 1 kilohertzs.

Chapter 7: Discussion AND CONCLUSION

7.1: Discussion

Throughout the full continuance of this undertaking, three methods were used to implement the voice coevals which is:

Generating voice utilizing mathlab and integrate it into microcontroller

Using ISD2560 Playback/Recorder Chip

Using ISD4003 Playback/Recorder Chip


Upon the completion of our undertaking The Talking Voltmeter, It is realized that in certain facets of the undertaking it is non done every bit best as possible due to the clip constrain and other ineluctable factors. But, in the old ages to come there may be another opportunity for betterment with the current engineering rocketing in clip. However there are certain restrictions in The Talking Voltmeter. The restrictions and suggested betterment methods are listed as below:

Restriction 1: Display System.

Improvement: Better Display System such as coloring materials LCD Display to bespeak the measuring and other utile information in a better position.

Restriction 2: Insufficient measurement options

Improvement: The voltmeter should be added with more characteristics where it is converted into multimeter.

Restriction 3: Low quality talker.

Improvement: Better quality talkers which would be suited for the Talking Voltmeter.

Restriction 4: High ingestion of country.

Improvement: Should be compact and versatile for easy mobility.

This undertaking can easy be commercialized for usage in labs. It is utile for any electrical applied scientist, as the speaking capableness comes in ready to hand when debugging a complicated circuit and non being able to look at the show. The mean and frequence metre is besides one of its sort characteristics for this device, and are decidedly utile in lab. Therefore, if decently bound and manufactured, this device has great potency.

7.3: Ethical Consideration

I believe my undertaking to the full follows the guidelines discussed in the IEEE Code of Ethics. While working in lab, I ensured that my undertaking did non adversely affect the safety, wellness, and public assistance of the populace. I used the most accurate of instruments to compare my informations with, and made every attempt to hold accurate informations, as my information is the norm of 3 or more tests.

My undertaking besides improved the apprehension of engineering as some of my characteristics are one of a sort non implemented in any device before. I besides improved my proficient competency by developing a Fuller apprehension of the PIC microcontroller, address coevals, playback/recorder bit operation and etc.

I know that my undertaking is non perfect and can still be improved in many ways. I am willing to take any constructive unfavorable judgment that would better this undertaking. I have besides acknowledged everyone responsible for assisting with my undertaking in assorted parts. My undertaking treats every individual utilizing it every bit.

Last, Is have besides ensured that my undertaking is safe and does non do any injury. I have made sure that my metal pins on the underside of the soldering board are non exposed. I will besides to the best of my ability assist other people with their undertaking and unfavorable judgments.

7.4: Decision

When I started this undertaking, I had a batch of aims to be achieved but I had one really of import aim in manus which is to larn how to trouble-shoot and larn most of the proficient parts of this undertaking as I will be graduating as an electrical and electronic applied scientist.